One of the person records in my database shows two marriages - one is correct; the other is shown as [F1454] *Not found*. This family record is not accessible under search, under reuse-code, or under find duplicates. There is so far as I can see no associated family rectangle. I cannot delete the reference because 'delete' is greyed out. Repair database does not help. I tried exporting a GEDCOM file and reimporting it, which cured the problem but lost me all my notes.

When I import the family into TreeDraw to draw a descendant tree, two marriages are shown between the same pair of people, with the data in one marriage and just the spouse's name in the other.

It could be a problem in the Links table but if Repair is not fixing it I would go with exporting as a GEDCOM and then importing it into a new database.

GEDCOM will transfer your notes but you need to make sure that this option is switched on in the GEDCOM export options as well as setting the privacy level correctly. Also, please make sure that you turn on all the GEDCOM export options which will preserve all Kith and Kin specific data and set the Receiving file system to Kith and Kin.